- lexer and parser reentrant
- line number handling automatic

Caveats:
- The preprocessor is still not thread-safe and full of bugs. I have another not-yet-ready patch to replace the preprocessor.
- The grammar files use options that are not supported by the old versions of flex and bison checked into compiler/tools. So I need to check-in the generated lexer-parser along with a shell script to generate them.

Review URL: http://codereview.appspot.com/2992041

git-svn-id: https://angleproject.googlecode.com/svn/trunk@475 736b8ea6-26fd-11df-bfd4-992fa37f6226